Presentation on theme: "GG3019/GG4027/GG5019 An Introduction to"— Presentation transcript:
1GG3019/GG4027/GG5019 www.abdn.ac.uk/geospatial An Introduction to Geographical InformationTechnology and GISSystems and GeospatialData AnalysisDavid R. GreenG12 – 2324
2GeoDatabase Data Models What is a geodatabase (data model)ESRI’s ArcGIS Geodatabase Data ModelsMarine Data Model (MDM)Application of the MDM (separate PPT)
3Data Models ESRI ArcGIS (successor to ArcView) GeoDatabase The geodatabase provides the common data access and management framework for ArcGIS that enables you to deploy GIS functionality and business logic wherever it is needed—in desktops, servers (including the Web), or mobile devices. With this architecture you have the tools to assemble intelligent geographic information systems (ESRI)
4Data Models ArcGIS has a well-defined model for working with data This generic model, called the geodatabase (short for geographic database), defines all the types of data that can be used in ArcGIS—for example, features, rasters, addresses, and survey measurements—and how they are represented, accessed, stored, managed and processed.The geodatabase is a common framework shared by all ArcGIS products and applications.
6Data Models(Geo)relational modelGeodatabase model
7Object-oriented data modeling lets you characterize features more naturally by letting you define your own types of objects, by defining topological, spatial, and general relationships, and by capturing how these objects interact with other objects.
8Data ModelsThe goal for the ArcGIS Data Models is to provide a practical template for implementing GIS projects.Common starting point results in the creation of data model design templates that simplify the integration of similar data sets at the local, state/provincial, national, and global levels.
9Data Models The geodatabase offers you the ability to: Handle rich data types.Apply sophisticated rules and relationships.Access large volumes of geographic data stored in both files and databases.The geodatabase is more than a manager of geographic data, it also implements sophisticated business logic that, for example, builds relationships between data types, such as topologies and geometric networks; validates data; and controls access.
10Data ModelsThe geodatabase supports multiple formats of spatial data including:· Simple features such as shape files· Custom features with business logic and editing rules· Attribute data· Metadata· Images· Raster/Grid data· CAD data
14Data Models How does a GIS data model work? An ArcGIS data model is written in a graphical model language (Visiotm) that provides both a diagram of the data structure as well as UML (Universal Modeling Language) code.UML code can be directly ported to the GIS to create an empty database structure defining all of the necessary relationships and dependencies.
21Marine Data ModelThe marine data model development will provide data managers with a readymade model for marine data so that they can spend more time at sea collecting data and in the lab analyzing their information, and less time at the computer planning the data structure. It should also be useful to GIS practitioners working as academic, government, or military oceanographers, coastal and marine resource managers, consultants, technologists, archaeologists, conservationists, geographers, fisheries managers, scientists, ocean explorers, and mariners alike (ESRI)
22What is the MDM? A geodatabase template A new way to spatially model marine dataA database used to assemble, store and query dataModel that captures the behavior of real-world objectsThe MDM model provide ready-to-use framework, built on accepted standards, for modeling and capturing the behavior of real-world objects in a geodatabase.Provide a way to effectively integrate 3D and 4D space and time. This is important because need for model to represent the multidimensional and dynamic nature of ocean data and processes.Do I need to go into detail about what a geodatabase is??
23Purpose of Marine Data Model Basic template for implementing GIS projectsinput, formatting, geoprocessing, creating maps, performing analysesBasic framework for writing program code and maintaining applicationsdevelopment of tools for the communityPromote networking and data sharing through established standards
24Georelational to Geodatabase Model Coverage (Arc/Info) and shapefile (ArcView) data structuresFeatures are aggregated into homogenous collections of points, lines, and polygons with generic, 1- and 2-dimensional "behavior"Can’t distinguish behaviorsPoint for a marker buoy, same as point for any observation“Smart Features” in a geodatabase
25Geodatabase Concepts ESRI's new data object-oriented data model objects, features, behaviorsObjectin ArcGIS an object is non-spatialit is NOT a point, line, or areait has no geographic locationit has no shape attribute in its tableship, vehicle, … customer, lake, houseFeaturean object that has geographic locationa point, line, area, TIN, raster
26Geodatabase Concepts Geodatabase Collection of feature data sets, rasters, TINsAll data in relational tablesBehavior is coupled with features through rulesNo more division between ARC and INFO (as in ESRI’s older GIS ArcInfo)
27Data ModelsThe common marine data types listed here are evolving and changing with review of the data model.
28The primary ESRI feature classes are the building blocks of the data model. These are the most commonly used features that provide a topological structure for the underlying data.
29Steps in Data Model Process Data model template – few weeks to monthsMature data model – up to few yearsDraftModelReview,ProjectsFinal Model
30Steps in Data Modeling (1) Model the user's view of data what are the basic features needed to solve the problem?(2) Select the geographic representationpoints, lines, areas, rasters, TINs(3) Define objects and relationshipsdraw a UML diagram(4) Match to geodatabase elementsspecify relationships, “behaviors”(5) Organize geodatabase structure
36Some of the benefits of the geodatabase data model are: • A uniform repository of geographic data. All of your geographic data can be stored and centrally managed in one database.• Data entry and editing is more accurate. Fewer mistakes are made because most of them can be prevented by intelligent validation behavior. For many users, this alone is a compelling reason to adopt the geodatabase data model.• Users work with more intuitive data objects. Properly designed, a geodatabase contains data objects that corresponds to the user’s model of data. Instead of generic points, lines, and areas, the user works with their objects of interest suchas transformers, roads, and lakes.• Features have a richer context. With topological associations, spatial representation, and general relationships, you not only define a feature’squalities, but its context with other features. This lets you specify what happens to features when a related feature is moved, changed, or deleted. This context also lets you locate and inspect a feature that is related to another.
37Better maps can be made. You have more control over how features are drawn and you can add intelligent drawing behavior. You can apply sophisticated drawing methods directly in ArcInfo’s mapping application, ArcMap. Highly specialized drawing methods can be executed through writing software code.Features on a map display are dynamic. When you work with features in ArcInfo, they can respond to changes in neighboring features. You can also associate custom queries or analytic tools with features.Shapes of features are better defined. The geodatabase data model lets you use define the shapes of features using straight lines, circular curves, elliptical curves, and Bezier splines.Sets of features are continuous. By their design, geodatabases can accomodate very large sets of features without tiles or other spatial partitions.Many users can edit geographic data simultaneously. The geodatabase data model supports work flows where many people can edit features in a local area, and then reconcile any differences that emerge.